/*-------------------------------------------------------------------------
 *
 * wait_error.c
 *        Convert a wait/waitpid(2) result code to a human-readable string
 *
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *      src/common/wait_error.c
 *
 *-------------------------------------------------------------------------
 */

#ifndef FRONTEND
#include "postgres.h"
#else
#include "postgres_fe.h"
#endif

#include <signal.h>
#include <sys/wait.h>

/*
 * Return a human-readable string explaining the reason a child process
 * terminated. The argument is a return code returned by wait(2) or
 * waitpid(2). The result is a translated, palloc'd or malloc'd string.
 */
char *
wait_result_to_str(int exitstatus)
{
    char        str[512];

    if (WIFEXITED(exitstatus))
    {
        /*
         * Give more specific error message for some common exit codes that
         * have a special meaning in shells.
         */
        switch (WEXITSTATUS(exitstatus))
        {
            case 126:
                snprintf(str, sizeof(str), _("command not executable"));
                break;

            case 127:
                snprintf(str, sizeof(str), _("command not found"));
                break;

            default:
                snprintf(str, sizeof(str),
                         _("child process exited with exit code %d"),
                         WEXITSTATUS(exitstatus));
        }
    }
    else if (WIFSIGNALED(exitstatus))
#if defined(WIN32)
        snprintf(str, sizeof(str),
                 _("child process was terminated by exception 0x%X"),
                 WTERMSIG(exitstatus));
#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
    {
        char        str2[256];

        snprintf(str2, sizeof(str2), "%d: %s", WTERMSIG(exitstatus),
                 WTERMSIG(exitstatus) < NSIG ?
                 sys_siglist[WTERMSIG(exitstatus)] : "(unknown)");
        snprintf(str, sizeof(str),
                 _("child process was terminated by signal %s"), str2);
    }
#else
        snprintf(str, sizeof(str),
                 _("child process was terminated by signal %d"),
                 WTERMSIG(exitstatus));
#endif
    else
        snprintf(str, sizeof(str),
                 _("child process exited with unrecognized status %d"),
                 exitstatus);

    return pstrdup(str);
}
